<?php
$filename = 'a.txt';
//a模式  是要往后叠加的  a模式的指针总是在最后面
$handle = fopen($filename,'a+');
fwrite($handle,'向军大叔');
//fseek($handle,0);
fclose($handle);
$file = fopen($filename,'r');
echo fread($file,filesize($filename));